1. Field of the Invention
The present invention relates to a cathode ray tube. More particularly, the present invention relates to an implosion preventing band for a cathode ray tube, in which the implosion preventing band prevents the scattering of glass if a bulb of the cathode ray tube implodes and includes degaussing coil supports for the mounting of a degaussing coil(s).
2. Description of the Related Art
Metal parts are typically found in a cathode ray tube (CRT). Such metal parts include (a) a color selection apparatus including a shadow mask that has a plurality of apertures for performing color separation of three electron beams, which are emitted from an electron gun, to corresponding R (red), G (green), B (blue) phosphors of a phosphor screen, and a mask frame for fixedly supporting the shadow mask at a predetermined location in the CRT; and (b) an inner shield for shielding from the earth's magnetic field a path through which the electron beams traject.
However, the metal parts nevertheless are exposed to and are magnetized by the earth's magnetic field so that a magnetic field is formed in the peripheries of the metal parts. This magnetic field formed in the peripheries of the metal parts changes the paths through which the electron beams traject such that the intended phosphors are not illuminated by the electron beams. That is, mis-landing of the electron beams occurs, and this reduces picture quality.
To remedy this problem, a degaussing coil(s) is mounted on an outer surface of a funnel of the CRT. The degaussing coil operates for a period of three to four seconds each time the CRT is turned on, during which time a degaussing current is used to demagnetize the metal parts.
An implosion preventing band that applies a predetermined compressive force to a bulb of the CRT is mounted to an outer surface of the bulb, particularly to an outer surface of a skirt of a face panel of the bulb. The implosion preventing band prevents scattering of glass if a crack formed in the bulb causes the same to implode.
Research is being performed on technology in which the implosion preventing band is used for mounting degaussing coils. U.S. Pat. No. 5,057,929 by Hermann for Cathode Ray Tube Having Implosion Band with Raised Tabs and Method and U.S. Pat. No. 5,181,123 by Swank for Cathode-Ray Tube Having a Shrinkfit Implosion Protection Band with Tension Limiting Means disclose configurations in which a plurality of protrusion tabs or clip receivers are formed on an outer circumference of an implosion preventing band, and a degaussing coil(s) is mounted using the protrusion tabs or clip receivers.
However, the protrusion tabs or clip receivers are typically made by a punching or piercing process such that sharp burrs are formed along edges of the protrusion tabs or clip receivers. Accordingly, if a degaussing coil(s) is mounted using an implosion preventing band that includes such protrusion tabs or clip receivers, the burrs may injure a worker or damage the insulation of the degaussing coils. If burrs are formed in areas contacting the bulb, the burrs may scratch the surface of the bulb such that it more easily explodes when receiving a shock.
Further, with such a structure of the conventional implosion preventing band, it is not possible to vary the positioning of the degaussing coils without re-structuring the entire implosion prevention band. That is, once formed, the protrusion tabs or clip receivers allow for only a single mounting configuration of the degaussing coils and varying the same requires a corresponding change in where the protrusion tabs or clip receivers are formed on the implosion preventing band. Accordingly, no flexibility is provided with respect to varying the mounting position of the degaussing coils.